Wellhole notcher



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April 30, 1968 G. s. GRUBB WELLHOLE NOTCHER Filed May 27, 1966 FIG. 6. \W'

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April 30, 1968 G. s. GRUBB WELLHOLE NOTCHER 3 Sheets-Sheet 2 Filed May 2'7, 1966 'I'NVENTQR. 650565 3 69055 nrrole/vvs.

April 30, 1968 G. s. GRUBB WELLHOLE NOTCHER 3 Sheets-Sheet 3 Filed May 27, 1966 62'0665 s. Gar/e5,

United States Patent 3,380,544 WELLHOLE NOTCHER George S. Grubb, 514 W. Walnut St, Titusville, Pa. 16354 Filed May 27, 1966, Ser. No. 553,574 9 Claims. (Cl. 175-289) This invention relates to well boring apparatus, and more particularly to a device for notching a Well bore in order to facilitate the penetration of fluid from the bore into adjoining formations.

A main object of the invention is to provide a novel and improved well bore notching apparatus which is relatively simple in construction, which is easy to operate, and which effectively notches or cuts through accumulated compacted material on the interior surface of a well bore so as to facilitate the passage of fluid or other material into the surrounding formations from the bore.

A further object of the invention is to provide an improved notching apparatus for a well bore, the apparatus involving relatively inexpensive components, being easy to install in a well, being durable in construction, being reliable in operation, and utilizing the force of gravity for its operation so that it is highly economical and inexpensive to operate.

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, in which:

FIGURE 1 is a vertical cross-sectional view showing an improved notching apparatus according to the present invention in association with and operatively located in a well bore, the well bore being shown in dotted view.

FIGURE 2 is a side elevational view of the notching apparatus of FIGURE 1, shown with the outer sleeve portion of the apparatus in its fully-lowered position and with the notching blade thereof extended.

FIGURE 3 is a vertical cross-sectional view taken substantially on the line 3-3 of FIGURE 2.

FIGURE 4 is an enlarged horizontal cross-sectional view taken substantially on the line 4-4 of FIGURE 2.

FIGURE 5 is an enlarged horizontal cross-sectional view taken substantially on the line 5-5 of FIGURE 3.

FIGURE 6 is an enlarged fragmentary vertical crosssectional view taken through the apparatus substantially on the line 6-6 of FIGURE 1.

FIGURE 7 is a vertical cross-sectional view taken substantially on the line 7-7 of FIGURE 6.

FIGURE 8 is an enlarged horizontal cross-sectional view taken substantially on the line 8-8 of FIGURE 3.

FIGURES 9 and 9a are enlarged perspective views with parts broken away, of the main guide cam and elements associated therewith and the guide collar cooperating with the cam assembly, as employed in the notching apparatus of FIGURES l to 3, the parts being shown in separated positions.

FIGURE 10 is an enlarged perspective view of the notching block members and cooperating stop blocks employed in the notching apparatus of FIGURES l to 3, these parts being shown in separated positions.

FIGURE 11 is an enlarged cross-sectional view taken through one of the notching blades substantially on the line 11-11 of FIGURE 10.

FIGURE 12 is a fragmentary vertical cross-sectional view substantially similar to FIGURE 7, but showing a different means for controlling the movement of the notching block members.

FIGURE 13 is a horizontal cross-sectional view taken substantially on the line 13-13 of FIGURE 12.

Referring to the drawings, 12 generally designates a well bore which has been formed by conventional drilling methods, and which may have accumulated an impacted 3,380,544 Patented Apr. 30, 1968 or highly-glazed interior surface which interferes with or substantially reduces the flow of fluid into the surrounding formations from the bore. In order to render the wall of the well more permeable and to provide a means for piercing or cutting through this relatively impervious inside coating or barrier, it is necessary to notch out the interior of the bore. Designated generally at 13 is an apparatus for notching the interior of the well bore, the apparatus being constructed in accordance with the present invention.

The notching apparatus 13 comprises an elongated generally cylindrical outer casing 14 having a circular top wall 15 provided with :an upstanding externally-threaded stud 16 adapted to be threadedly-engaged in the bottom of a supporting collar member 17 (FIGURE 1) which is, in turn, supported by a cable 18 whereby the apparatus may be lowered into the well bore 12 and whereby the casing 14 may be thereafter raised and lowered to operate the apparatus, as will be presently described.

Secured in the upper portion of the generally cylindrical casing 14 is an annular internal collar 19, the collar 19 being secured in said upper portion of casing 14 by a plurality of fastening bolts 20 engaged through the wall of casing 14 and threaded into tapped openings 21 provided in collar 19.

The inside wall of collar 19 is formed with diametrically-opposed vertical grooves 22, 22.

Designated generally at 23 is the main cam guiding assembly of the apparatus, said assembly comprising an elongated bar-like main body 24 having arcuately-shaped opposite edges 25, 25 and being slidably-engageable inside the casing 14 with said opposite edges 25, 25 in sliding contact with diametrically-opposite inside surface portions of the casing. The opposite side edges of the bar member 24 are formed with guide grooves 26 extending from the major portions of their lengths which slidablyreceive diametrically opposite guide blocks 27, 27 secured in the lower end portion of the sleeve member 14, as by fastening bolts 28, 28 engaged through the wall of the casing, as shown in FIGURE 8. The body 24 is integrallyformed at its lower end with an enlarged, downwardlyconvex, generally frusto-conical shoulder portion 30 which is secured to the top end of a depending vertical post member 31 adapted to abut the bottom end of the well bore 12 so as to support the assembly 23 at a definite substantially fixed level in the well bore. The post member 31 may be of any desired length, depending upon the portion of the well bore to be notched by the apparatus.

Secured to the lower portion of the casing 14 are a pair of opposing arcuately-shaped stop blocks 32, 32 having parallel flat inside surfaces 33, 33 spaced to slidablyreceive the-body 24 therebetween. The inside surfaces 33, 33 of blocks 32, 32 are formed centrally with vertical grooves 35, 35 aligned with the vertical grooves 22, 22 in the top collar member 19.

A pair of similar arcnate block members 36, 36 are secured in opposing relationship in the sleeve member 14 above and spaced from the block members 32, 32 being similar in construction to said block members and being respectively vertically-aligned therewith. The block members 36, 36 have arcuately-curved outer surfaces conforming with the interior surface contour of sleeve member 14 and are provided with the flat parallel opposing inner surfaces 37, 37 similar to the surfaces 33, 33 of the lower block members 32, 32. Similarly, the block members 36, 36 are formed on their inside flat surfaces with vertical grooves 38, 38 aligned with grooves 35, 35 and 22, 22.

The sleeve member 14 is formed between the pairs of blocks 32, 32 and 36, 36 with diametrically-opposed vertical slots 39, 39 and slidably-engaged through said slots are the respective vertical blade portions 40 of a pair of blade block members 41, 41, said block members being slidablydisposed between the top and bottom fixed blocks 36, 36 and 32, 32 and being provided with arcuate main body portions 42 integral with the blades 40, whereby the blade blocks 41 are generally T-shaped in horizontal cross-section. The head portions 42 of the T-shaped blocks 41 are provided with flat inside surfaces 43 which are parallel to each other and which are slidably-engageable with the opposite fiat guide surfaces 44, 44 of the main guide body 24. Thus, the head portions 42 of the block members 41 have substantially the same horizontal cross-sectional shape and size as the top and bottom block members 36 and 32. The outer ends of the blades have downwardly and outwardly-inclined beveled edge surfaces 45 so as to define acute-angled cutting points 46 at their outer bottom corners. The head portion-s 42 of the blocks are provided with downwardly and outwardly-inclined guide bores 47 which are symmetrically-located relative to the main guide body 24.

Secured to the lower portion of casing 14 immediately above the slots 39, 39 are respective vertical support plates 48, 48 whose bottom edges are located substantially at the same level as the top edges of the slots 39, 39 and which are of substantial thickness so that they provide increased downward bearing areas on the top edges of the blade elements 40 when the casing member 14 is allowed to gravitate downwardly during the operation of the apparatus 13.

The plate members 48, 48 also cooperate with the inside surface of the well bore 12 to assist in guiding the casing member 14 vertically and in properly centering the guide assembly 23 when the apparatus is lowered into the well bore. A pair of similar arcuate guide plates or blocks 49, 49 are secured on the casing 14 above the blocks or plates 48, 48 and at angular positions 90 away from the position-s of the blocks 48, 48 relative to the axis of easing member 14, as shown in FIGURES 2 and 8.

The cam guide body 24 is formed at its top end with the upwardly-convergent tapered tip 50 of triangular cross-sectional shape, defined by the upwardly-convergent flat surfaces 51, 51 rising from the opposing fiat surfaces 44, 44 of body 24. The opposite edges of the tip 50 terminate inwardly of the arcuately-curved opposite edges of the body 24 at upwardly-facing stop shoulders 52, 52 engageable with the bottom rim of collar member 19 to limit the downward movement of easing member 14 relative to the main guide assembly 23. This limiting action is in cooperation with positive limiting action provided by the engagement of the bottom ends of blocks 32, 32 with the shoulders defined at the opposite sides of the downwardly-convergent frustro-conical bottom member 30.

The top end of the guide body 24 is formed with a vertical bore 54 which receive-s the stem 55 of a generally T-shaped cam member 56, the stem 55 being received in the bore 54 and being retained in the bore 54 by a locking stud 57 engaged through a tapped opening 58 in the upper portion of the body 24 and communicating with the bore 54, the stud 57 being received in a locking groove 59 provided in the lower end of the stem 55, whereby the member 56 is held in a substantially fixed position relative to the body 24 above and transverse to tip 50. The cam member 56 is provided with the top bar 60 which terminates in respectively downwardly and outwardly-inclined finger elements 61, 61 having substantially the same inclinations as the bores 47, 47 of the blade blocks 41, 41 and being adapted to slidably-engage therein and to cam the blocks 41, 41 inwardly and outwardly responsive to downward and upward movement respectively of the finger elements 61, 61 in the inclined bores 47, 47. The ends of the finger elements 61, 61 are also slidably-engageable in the grooves 22, 22 of collar 19, the grooves 38, 38 of the blocks 36, 36 and the grooves 35, 35 of the blocks 32, 32.

In ope-ration, the apparatus is lowered into the well bore 12 in the manner illustrated in FIGURE 1, the member 24 being in its lowered position relative to the shell .4 member 14 and remaining in this lowered position until the bottom end of the depending shaft element 31 engages the bottom of the bore. When this occurs, the member 24 is held against further downward movement; and as the shell member 14 continues to descend, the cutters 41, 41 are cammed outwardly by the cooperation between the inside surfaces 43, 43 thereof and the downward-lydivergent surfaces 51, 51 of member 24. After the cutters 41, 41 have moved downwardly past the tapered top end portion of member 24, the cutters remain in their extended positions and continue to travel downwardlywvith the sleeve member 14, cutting out grooves 75, as shown in FIGURE 2, in the well bore 12. These grooves 75 cut through the impacted or glazed inside surface. of the bore and serve to improve the porosity of the bore hole so as to release fluids into the adjacent formations so that said fluids can fiow outwardly from the bore hole.

When the shell member 14 has reached the downward limit of its movement, the shell member 14 may be again elevated by means of cable 18 to a position such as that illustrated in FIGURE 1, wherein the cutter members 41, 41 are retracted, after which shell member 14 may be rotated and another cutting stroke may be performed by lowering the shell member.

The length of the cutting stroke may be varied by adjusting the position of the collar member 19 within the shell member 14. For this purpose, spaced pairs of diametrically-opposed sets of fastening-screw apertures 76, 76 are provided along the length of the shell member 14, the pairs of apertures 76, 76 being registrable withthe tapped openings 21 of collar member 19 to receive the fastening screws 20.

The arrangement shown in FIGURES 1 and 2 illustrates a condition providing the maximum cutting stroke, inasmuch as the collar member 19 is fastened at its uppermost position in the shell member 14. With this arrangement, the collar member 19 engages shoulders 52, 52 to limit the downward movement of the shell member 14 relative to the guide member 24. When the collar member 19 is secured in a lower position in the shell member 14, as above-described, employing a selected set of fastening apertures 76, the downward movement of the shell member 14 is again limited only by the cooperation of the collar member 19 with the stop shoulders 52, 52 on the guide member 24.

It will be noted that the mechanical notching apparatus above-described is adaptable to installations of the type employing cable-controlled drilling tools, utilizing a cable, such as the cable 18.

In the modified form of the apparatus shown in FIG- URES 12 and 13, the member 56 is omitted, and in place thereof a transverse vertical spring bar 80 is engaged through a vertical slot 81 provided in each blade element 40, the opposite ends of the spring bars -80 being received in an annular internal groove 82 provided in the casing 14. When the blade elements 40 are cammed outwardly by the engagement of their inner ends with the tapered tip 50 to their dotted-view positions of FIGURE 12, the spring bars 80, 80 assume arcuate configurations in the groove 82, as shown in dotted view in FIGURE 13, and develop restoring tension which acts to retract the blade elements when casing 14 is elevated and when blade ele ments 40, 40 move upwardly relative to the tapered tip 50.

An important feature of the invention is that all measurements relating to the location of placement of the notches are taken from the bottom of the bore hole. Thus, the downwardly-divergent cam surfaces 51, 51 are located in a definite position. By changing the length of the anchor member 31, the position of said cam surfaces may be changed accordingly, which governs the location at which the notches are formed in the hole.

Another important feature of the present invention from the aspect of economy is that it is not necessary to run a string of pipe from the surface to the bottom of the well, or to employ water or sand, as is required with other apparatus heretofore employed.

It will be readily apparent that it is also possible to place the notches at any desired location in the well hole by varying the length of the bottom support shaft element 31 employed with the apparatus. The member 31 com prises a pipe of any desired length which is detachablysecured, for example, by threading or the like, to the downwardly-convergent frusto-conical member 30.

Another advantageous feature of considerable importance is that the apparatus forms a vertical notch which is quite clean and that there are no particles forced back into the sand or other material of the bore hole by the notching process, in contrast to the results obtained by processes heretofore employed in the prior art.

The cable 18 is operated in a conventional manner, for example, by a walking beam or similar mechanism.

While specific embodiments of an improved well bore notching apparatus have been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is:

1. In a well bore notching apparatus, abutment means engageable with the bottom of a bore hole, movable cutter means slidably-receivable in the bore hole, and cooperating means on the cutter means and the abutment means to move portions of the cutter means horizontally responsive to vertical movement of the cutter means relative to the abutment means, and wherein said abutment means comprises a vertical guide member and means to limit downward movement of the guide member in the well bore, and said cutter means includes an elongated shell member adapted to be placed in the well bore and to slidably-receive said guide member, and movable cutter members slidably-mounted in the wall of the shell member for inward and outward horizontal movement through the wall, and wherein said cooperating means comprises cooperating cam means on the top end of the guide member and on the cutter members moving the cutter members horizontally responsive to vertical movement of the shell member relative to the guide member.

2. The well bore notching apparatus of claim 1, and wherein the shell member wall is formed with a plurality of vertical slots at the same level and wherein said cutter members comprise block members slidably-mounted in said slots and having outer cutting blade elements.

3. The well bore notching apparatus of claim 2, and wherein there are two diametrically-opposed slots with a block member in each slot.

4. The well bore notching apparatus of claim 3, and stop means in the shell member and shoulder means on the guide member engageable with said stop means to limit the range of vertical movement of the shell member relative to the guide member.

5. The well bore notching apparatus of claim 4, and wherein said stop means includes a collar member mounted in the shell member, and wherein said shoulder means includes upwardly-facing opposing shoulders on the guide member subjacent the cam means on the top end of the guide member and engageable with the collar member.

6. The well bore notching apparatus of claim 1, and wherein said guide member is formed with a vertical edge groove, and a projection in the shell member slidably-engaged in said edge groove to prevent rotation of the shell member relative to the guide member.

7. The well bore notching apparatus of claim 1, and wherein said cooperating cam means comprises an upwardly-tapering tip on the top end of the guide member and the means maintaining the inner ends of the cutter members substantially in engagement with said tip.

8. The well bore notching apparatus of claim 7, and wherein said guide member has opposing parallel flat surfaces below said tip, and opposing internal blocks secured in the lower portion of the shell member slidably engaging said parallel flat surfaces.

9. The well bore notching apparatus of claim 7, and wherein the means maintaining the inner ends of the cutter members in engagement with the tip comprise respective transversely-extending spring bars engaged through the cutter members, the shell member being formed with internal recess means receiving the ends of the spring bars.

References Cited UNITED STATES PATENTS 1,821,473 9/1931 Mercer -289 FOREIGN PATENTS 322,059 9/ 1902 France. 322,874 10/ 1902 France. 1,121,402 4/ 1956 France.

157,3 64 12/ 1904- Germany.

CHARLES E. OCONNELL, Primary Examiner. DAVID H. BROWN, Examiner. 

1. IN A WELL BORE NOTCHING APPARATUS, ABUTMENT MEANS ENGAGEABLE WITH THE BOTTOM OF A BORE HOLE, MOVABLE CUTTER MEANS SLIDABLY-RECEIVABLE IN THE BORE HOLE, AND COOPERATING MEANS ON THE CUTTER MEANS AND THE ABUTMENT MEANS TO MOVE PORTIONS OF THE CUTTER MEANS HORIZONTALLY RESPONSIVE TO VERTICAL MOVEMENT OF THE CUTTER MEANS RELATIVE TO THE ABUTMENT MEANS, AND WHEREIN SAID ABUTMENT MEANS COMPRISES A VERTICAL GUIDE MEMBER AND MEANS TO LIMIT DOWNWARD MOVEMENT OF THE GUIDE MEMBER IN THE WELL BORE, AND SAID CUTTER MEANS INCLUDES AN ELONGATED SHELL MEMBER ADAPTED TO BE PLACED IN THE WELL BORE AND TO SLIDABLY-RECEIVE SAID GUIDE MEMBER, AND MOVABLE CUTTER MEMBERS SLIDABLY-MOUNTED IN THE WALL OF THE SHELL MEMBER FOR INWARD AND OUTWARD HORIZONTAL MOVEMENT THROUGH THE WALL, AND WHEREIN SAID COOPERATING MEANS COMPRISES COOPERATING CAM MEANS ON THE TOP END OF THE GUIDE MEMBER AND ON THE CUTTER MEMBERS MOVING THE CUTTER MEMBERS HORIZONTALLY RESPONSIVE TO VERTICAL MOVEMENT OF THE SHELL MEMBER RELATIVE TO THE GUIDE MEMBER. 